Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means that a part of the car that helps charge the battery is not working right because it’s getting too little power.
The Power Factor Correction Converter is part of the vehicle's charging system, and this code indicates that the voltage sensor is reading a voltage that is lower than expected.
The P1C66 code is triggered when the Universal Charger Extension Control Module detects that the voltage from the Power Factor Correction Converter is below the specified range. This could be due to a faulty sensor, wiring issues, or problems with the converter itself.
• Check Engine Light is on
• Battery not charging properly
• Reduced vehicle performance
• Faulty voltage sensor
• Damaged wiring or connectors
• Malfunctioning Power Factor Correction Converter
Power Factor Correction: A technique used to improve the efficiency of power delivery.
Voltage Sensor: A device that measures the voltage level in a circuit.
• Check for any other related trouble codes.
• Inspect the wiring and connectors for damage.
• Test the voltage sensor for proper operation.
• Replace the faulty voltage sensor.
• Repair or replace damaged wiring or connectors.
• Replace the Power Factor Correction Converter if necessary.
• OBD-II scanner
• Multimeter
• Screwdriver set
$150 - $400
Moderate
• Chevrolet Volt
• Nissan Leaf
• Toyota Prius
• Regular maintenance of the charging system
• Checking and securing electrical connections
• Using the correct charger for the vehicle
Sensor Issue
• Avoid using the vehicle until the issue is fixed to prevent battery damage.
• Consult with a professional mechanic for accurate diagnosis.
Check with your vehicle manufacturer for warranty coverage on electrical components.
This code has been associated with vehicles that have advanced charging systems and is more common in hybrid and electric vehicles.
Moderate – It should be addressed soon to avoid further charging issues.
Driving with a malfunctioning charging system can lead to battery failure, which could leave you stranded.
• Vehicle in 'ON' position
• Battery connected and charged
The Power Factor Correction Converter is typically located near the vehicle's battery or charging system.
Q: Can I drive my car with this code?
A: It's not recommended to drive for long periods as the battery may not charge properly.
Q: Will this code clear itself?
A: The code may clear if the issue is resolved, but it often requires manual clearing with an OBD-II scanner.
High-End · Full-system diagnostics
A full-system bidirectional platform aimed at advanced DIY users and professional diagnostic workflows.
Network faults often require full-system access instead of a generic code reader alone.
View on Amazon
Universal · Digital multimeter
A solid entry-level multimeter for voltage, continuity, resistance, and basic electrical troubleshooting.
Helpful for checking voltage drops, grounds, and basic circuit health when modules are not communicating.
View on Amazon
Universal · Wire connectors and repair kit
Useful when diagnosis points toward damaged wiring, corroded terminals, or connector repairs.
Useful if diagnosis points toward damaged connectors, wiring, or terminal repairs.
View on AmazonThese are optional diagnostic tools, not guaranteed fixes. As an Amazon Associate I earn from qualifying purchases.